Press die

ABSTRACT

A press die comprises an upper die and a lower die each including a die main body; at least one first guide post projected on one of the die main bodies of the upper die and the lower die; and a first product pressing member mounted on the one of the die main bodies so as to be slidable along a middle portion of the first guide post, at least one guide through hole through which a middle portion of the first guide post penetrates being formed in the first product pressing member. The die main bodies of both the upper die and the lower die and the first product pressing member undergo an alignment for each other through the first guide post by inserting a tip portion of the first guide post into a first guide hole formed on the other one of the die main bodies of the upper die and the lower die.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a press die, and more specifically, to a press die in which an alignment of die main bodies of both an upper die and a lower die is performed through guide posts.

[0003] 2. Description of the Related Art

[0004]FIG. 6 shows a configuration of a conventional press die for an automobile. This press die is one for cutting and bending and is provided with an upper die 1 and a lower die 2. The upper die 1 includes an upper die main body 3, and a pad 4 and upper die cutting and bending edges 5 which are fitted to the upper die main body 3. The pad 4 is slidably supported with respect to the upper die main body 3 in a state where it is depressed downward by springs 6, and is prevented from falling down from the upper die main body 3 while maintaining a necessary stroke by a stopper pin 7. On the other hand, the lower die 2 includes a lower die main body 8 and lower die cutting and bending edges 9 fixed to the lower die main body 8.

[0005] By setting a pressed product 10 on a molding surface 11 of the lower die main body 8 and starting the press die undergo clamping, the pressed product 10 is first pressed and fixed between a molding surface 12 of the pad 4 and the molding surface 11 of the lower die main body 8. When the distance between the upper die 1 and the lower die 2 is further narrowed, the springs 6 are compressed against their urging forces so that the peripheral portion of the pressed product 10 is cut and bent with the upper die cutting and bending edges 5 and the lower die cutting and bending edges 9.

[0006] In order to mold the pressed product 10 with the thus-configured press die, the accurate alignment of the molding surface 12 of the pad 4 and the molding surface 11 of the lower die main body 8 is necessary. The alignment of the upper die main body 3 and the lower die main body 8 is performed by inserting guide posts 13 projected on the lower die main body 8 into guide holes 14 formed in the upper die main body 3. Further, as shown in FIG. 7, the relative positional relationship between the pad 4 and the upper die main body 3 is adjusted by interposing slide plates 15 between the side surface of the pad 4 and the upper die main body 3.

[0007] Further, FIG. 8 shows a configuration of another conventional press die for the automobile. This press die is one for drawing, and is provided with an upper die 16 and a lower die 17. A molding surface 19 is formed on an upper die main body 18 in the upper die 16. On the other hand, the lower die 17 includes a lower die main body 20 and a wrinkle pressing ring 22 slidably supported by cushion pins 21 on the lower die main body 20. Molding surfaces 23 and 24 are formed on the lower die main body 20 and the wrinkle pressing ring 22, respectively.

[0008] The wrinkle pressing ring 22 is pushed up by the cushion pins 21, and a material 25 to be molded is placed thereon. The upper die main body 18 is lowered to sandwich the material 25 between the upper die main body 18 and the wrinkle pressing ring 22. By lowering the upper die main body 18 and the wrinkle pressing ring 22 together under this state, the material 25 is pressed against the molding surface 23 of the lower die main body 20 and molded into a required shape.

[0009] Also in this press die, the accurate alignment of the molding surface 19 of the upper die main body 18, the molding surface 23 of the lower die main body 20 and the molding surface 24 of the wrinkle pressing ring 22 is necessary. The alignment of the upper die main body 18 and the lower die main body 20 is performed by inserting guide posts 26 projected on the lower die main body 20 into guide holes 27 formed in the upper die main body 18. Further, as shown in FIG. 9, the relative positional relationship between the wrinkle pressing ring 22 and the lower die main body 20 is adjusted by interposing slide plates 28 between the side surface of the wrinkle pressing ring 22 and the lower die main body 20.

[0010] The side surface of the pad 4 with which the slide plates 15 are in contact and the side surface of the wrinkle pressing ring 22 with which the slide plates 28 are in contact are formed using a tool such as an end mill through a completely different process from the formation of the molding surfaces of the pad 4 and the wrinkle pressing ring 22. Thus, it is difficult to perform alignment of the side surface and the molding surface with high precision. Therefore, the adjustments of the relative position between the pad 4 and the upper die main body 3 and of the relative position between the wrinkle pressing ring 22 and the lower die main body 20 are performed by temporary assembling the respective parts and manually replacing the slide plates 15 and 28.

[0011] However, since each of the molding surfaces is large in the press die for the automobile, the size and weight of the pad 4 and the wrinkle pressing ring 22 also become large, resulting in a problem in that a considerably large amount of effort and time is required in the adjustment of the relative position due to the replacement of the slide plates 15 or 28.

SUMMARY OF THE INVENTION

[0012] The present invention is made to solve the problem above, and an object of the present invention is to provide a press die which does not require manual adjustment of a relative position of each part.

[0013] A press die in accordance with the present invention comprises an upper die and a lower die each including a die main body; at least one first guide post projected on one of the die main bodies of the upper die and the lower die; and a first product pressing member mounted on the one of the die main bodies so as to be slidable along a middle portion of the first guide post, at least one guide through hole through which a middle portion of the first guide post penetrates being formed in the first product pressing member; the die main bodies of both the upper die and the lower die and the first product pressing member undergoing an alignment for each other through the first guide post by inserting a tip portion of the first guide post into a first guide hole formed on the other one of the die main bodies of the upper die and the lower die.

[0014] The press die adopts a method of sliding the first product pressing member using the first guide post for performing an alignment of the die main bodies of both the upper die and the lower die, thereby making an error in alignment of the die main bodies of both and the first product pressing member extremely small. Therefore, no adjustment of the relative position of the respective parts is required.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a cross-sectional view showing a press die in accordance with Embodiment 1 of the present invention;

[0016]FIG. 2 is a plan view showing a lower die of the press die of Embodiment 1;

[0017]FIG. 3 is a cross-sectional view showing a guide post used in the press die of Embodiment 1;

[0018]FIGS. 4 and 5 are cross-sectional views showing press dies in accordance with Embodiments 2 and 3, respectively;

[0019]FIG. 6 is a cross-sectional view showing a conventional press die;

[0020]FIG. 7 is a bottom view showing an upper die of the press die shown in FIG. 6;

[0021]FIG. 8 is a cross-sectional view showing another conventional press die; and

[0022]FIG. 9 is a plan view showing a lower die of the press die shown in FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0024] Embodiment 1

[0025]FIG. 1 shows a configuration of a press die for drawing in accordance with Embodiment 1 of the present invention. The press die comprises an upper die 31 and a lower die 32. A molding surface 34 is formed on an upper die main body 33 in the upper die 31. On the other hand, the lower die 32 includes a lower die main body 35 and a slidable wrinkle pressing ring 36 as a product pressing member. Guide posts 38 are projected upward on a peripheral portion of the lower die main body 35 from its molding surface 37 side, and guide holes 40 into which middle portions 39 of the guide posts 38 are to be inserted are formed in the wrinkle pressing ring 36. The guide holes 40 are formed from a molding surface 41 side of the wrinkle pressing ring 36, and guide bushes 42 as bearing members are fitted into the guide holes 40 on the molding surface 41 side. The guide posts 38 are inserted into the guide bushes 42 so that the wrinkle pressing ring 36 is slidably supported onto the lower die main body 35 with cushion pins 43. The sliding movement of the wrinkle pressing ring 36 with respect to the guide posts 38 can be smoothly conducted due to the existence of the guide bushes 42.

[0026] Further, in the upper die main body 33, guide holes 45 into which tip portions 44 of the guide posts 38 are to be inserted are formed from the molding surface 34 side, and guide bushes 46 are fitted into the guide holes 45. By inserting the tip portions 44 of the guide posts 38 into the guide holes 45, an alignment of the upper die main body 33 and the lower die main body 35 is performed.

[0027] As shown in FIG. 2, the wrinkle pressing ring 36 is formed into a circular shape so as to enclose the molding surface 37 of the lower die main body 35.

[0028] As shown in FIG. 3, in each guide post 38, a diameter D1 of the tip portion 44 which is to be inserted into the guide hole 45 of the upper die main body 33 is smaller than a diameter D2 of the middle portion 39 which is to be inserted into the guide hole 40 of the wrinkle pressing ring 36. Therefore, the wrinkle pressing ring 36 can be detached and attached easily with respect to the guide posts 38.

[0029] Next, the operation at the time of performing drawing with this press die will be described. First, the wrinkle pressing ring 36 is pushed up along the guide posts 38 by the cushion pins 43. A material 47 to be molded is placed on the molding surface 41 of the elevated wrinkle pressing ring 36, and the upper die main body 33 is then lowered to sandwich the material 47 between the upper die main body 33 and the wrinkle pressing ring 36. Under this state, by lowering the upper die main body 33 and the wrinkle pressing ring 36 together, the material 47 is pressed against the molding surface 37 of the lower die main body 35 to be molded into a required shape.

[0030] Since the guide posts 38 of the lower die main body 35 are fitted from the molding surface 37 side of the lower die main body 35, the guide posts 38 and the molding surface 37 are machined with high precision based on the common reference point for each other. Also, since the guide holes 40 of the wrinkle pressing ring 36 are formed from the molding surface 41 side, the guide holes 40 and the molding surface 41 are machined with high precision based on the common reference point for each other. Further, since the wrinkle pressing ring 36 and the lower die main body 35 undergo alignment through the guide posts 38, an alignment of the relative positional relationship between the molding surface 41 of the wrinkle pressing ring 36 and the molding surface 37 of the lower die main body 35 is performed with high precision. As a result, there is no need to adjust the relative position using slide plates as in the conventional die.

[0031] Further, since the guide holes 45 of the upper die main body 33 are formed from the molding surface 34 side of the upper die main body 33 and the tip portions 44 of the guide posts 38 are inserted into the guide holes 45, the upper die main body 33, the lower die main body 35 and the wrinkle pressing ring 36 undergo a mutual alignment through the common guide posts 38. As a result, an error in the alignment becomes extremely small.

[0032] That is, no temporary assembling of the die is required, and the die may be manufactured with fewer manufacturing steps in a short period of time. Also, the quality of pressed products manufactured with this press die are enhanced.

[0033] Embodiment 2

[0034] A configuration of a press die for drawing in accordance with Embodiment 2 is shown in FIG. 4. In this press die, middle portions 54 of guide posts 53 for aligning an upper die main body 51 with a lower die main body 52 penetrate through guide holes 56 of a lower die wrinkle pressing ring 55. In addition, in this press die, an upper die wrinkle pressing ring 59 is mounted on the upper die main body 51 so as to be slidable along guide posts 58 with springs 57 or cylinders. Tip portions 60 of the guide posts 53 are inserted into guide holes 62 which are formed in the upper die main body 51 from its molding surface 61 side.

[0035] The guide posts 58 are fitted on the upper die main body 51 from its molding surface 61 side, and guide holes 63 into which the guide posts 58 are to be inserted are formed on the upper die wrinkle pressing ring 59 from its molding surface 64 side.

[0036] In this structure, the molding surfaces of the lower die main body 52 and the upper die main body 51 and the molding surfaces of the lower die wrinkle pressing ring 55 and the upper die wrinkle pressing ring 59 undergo positional adjustment with high precision for each other without adjusting the relative position using slide plates or the like.

[0037] Embodiment 3

[0038] A configuration of a press die for drawing in accordance with Embodiment 3 is shown in FIG. 5. This press die is configured, in the press die of Embodiment 2 shown in FIG. 4, such that an upper die punch 73 is further mounted to an upper die main body 71 so as to be slidable along guide posts 72. The guide posts 72 are fitted on the upper die punch 73 from its molding surface side, and guide holes 74 into which the guide posts 72 are to be inserted are formed in the upper die main body 71 from its molding surface side.

[0039] The tip portions 60 of the guide posts 53 projected on the lower die main body 52 are inserted into guide holes 75 formed in the upper die main body 71 from its molding surface side.

[0040] In this structure, the molding surfaces of the lower die main body 52 and the upper die main body 71, the molding surfaces of the lower die wrinkle pressing ring 55 and the upper die wrinkle pressing ring 59 and the molding surface of the upper die punch 73 undergo positional adjustment with high precision for each other without adjusting the relative position using slide plates or the like.

[0041] In each of the above-mentioned Embodiments 1 to 3, the press die for drawing is described. However, the present invention is not limited thereto, but may also be applied to the press die for cutting and bending as that shown in FIG. 6.

[0042] Further, in each of Embodiments 1 to 3, the positional relation between the upper die and the lower die may be made inverse. That is, the press die may be constructed such that: the guide posts are projected downward on the upper die main body; the product pressing member such as the wrinkle pressing ring or the pad is slidably mounted along the middle portions of the guide posts; and the tip portions of the guide posts are inserted into the guide holes of the lower die main body. 

What is claimed is:
 1. A press die comprising: an upper die and a lower die each including a die main body; at least one first guide post projected on one of the die main bodies of the upper die and the lower die; and a first product pressing member mounted on the one of the die main bodies so as to be slidable along a middle portion of the first guide post, at least one guide through hole through which a middle portion of the first guide post penetrates being formed in the first product pressing member; the die main bodies of both the upper die and the lower die and the first product pressing member undergoing an alignment for each other through the first guide post by inserting a tip portion of the first guide post into a first guide hole formed on the other one of the die main bodies of the upper die and the lower die.
 2. A press die according to claim 1 wherein the first guide post is formed such that a diameter of the tip portion which is to be inserted into the first guide hole is smaller than a diameter of the middle portion which penetrates through the guide through hole of the first product pressing member.
 3. A press die according to claim 1 further comprising a bearing member fitted into the guide through hole of the first product pressing member on its molding surface side for slidably receiving the middle portion of the first guide post.
 4. A press die according to claim 1 further comprising a bearing member fitted into the first guide hole of the other die main body for slidably receiving the tip portion of the first guide post.
 5. A press die according to claim 1 further comprising: at least one second guide post attached to at least one of the die main bodies of the upper die and the lower die from its molding surface side; and at least one second product pressing member mounted to the die main body to which the second guide post is attached so as to be slidable along the second guide post, at least one second guide hole into which the second guide post is to be inserted being formed in the second product pressing member from its molding surface side.
 6. A press die according to claim 5 further comprising a bearing member fitted into the second guide hole of the second product pressing member on its molding surface side for slidably receiving the second guide post. 